The micro-friends in our nasal cavity!
27th June is marked as the “World Microbiome Day” for celebrating microbial world and this week, several events are organized for discussing ongoing microbiome related research. We can hear a lot about diverse world of microbiome and its impact on human health and environment. We know the role our gut microbiome plays in maintaining our health and any alteration in this microbial community can lead to disease condition. Besides gut microbiome, the other community that steals my attention is our nasal microbiome.
Do you sneeze often??
It is a general conception that sneezing is common in winters possibly due to seasonal variation. But have you ever experienced or noticed someone sneezing or showing flu like symptoms (running nose, tearing eyes, mucus/phlegm in throat, itching in the ear) in summers, that too during the heat wave when most of the people are chilling in ACs or coolers! Considering my own problems with such flu like symptoms, mostly common throughout all the seasons or weather conditions, knowing nasal microbiome was of my interest.
Nasal microbiome and respiratory infections
As other parts of our body like gut, skin, oral or urogenital apparatus harbors a characteristic bacterial diversity, our nasal cavity also inhabits a diversity of commensal microbes attached to the epithelium (covering surface) so that they are not wiped off as we inhale. Their major role is to protect us from invading pathogens. The friendly microbes in our nose, sinuses (air filled spaces near the nasal cavity) or respiratory tract fight with invading pathogens for space and nutrients; and under healthy conditions they win and do not let pathogens to grow or colonize. If the fight persists, these microbes secrete toxic substance that kills the pathogen and as a response to this immunological reaction, we develop symptoms like runny nose or congestion for a short period of time, if taken care properly, the condition does not aggravate. However, like for gut microbiome, dysbiosis in microbial biodiversity can lead to diseased condition, similarly imbalance in the nasal microbial community can greatly impact our health by colonization of pathogens. The pathogenic overgrowth in our nose or nasal cavity can then further expanse to respiratory tract making us more susceptible to allergies and respiratory infections like rhinitis (inflammation of nose or nasal passage causing nasal itching, runny nose and sneezing), sinusitis (inflammation of sinuses leading to facial pain and other symptoms similar to rhinitis) or asthma (inflammation of respiratory airways causing difficulty in breathing).
Our nose and respiratory tract are the major route for contact with environment and the primary barrier to harmful substances is provided by hairs in our nose. But, if you are allergic to some environmental substances (allergens) like pollens, dust particles, mold which varies according to location and seasonal conditions, you can recall sneezing repeatedly in a particular situation like getting up in the morning and immediately opening the window or moving out to breathe fresh air but ending up sneezing due to exposure to allergens in the air. Though, these micro particles are not that harmful for us but our immune system treat them as invaders as soon as they reach our mucus membranes in nose, eyes, throat and then the war begins! Studies have reported significant alteration in nasal microbial biodiversity in allergies and respiratory infections, which further accelerates pathological condition. This bacterial composition is altered under the influence of several factors like pollution, vaccination, hygiene and host health. Climatic factors like temperature, rainfall, humidity, atmospheric pressure also causes microbial shifts especially in sinuses. Further, the nasal microbiota composition influences immune response and hence the pathophysiology and development of infection. So, it is like microbiome alteration could be a cause or effect of such respiratory infections. A study reported that allergens act as a initiator stimulating nasal mucosa in allergic patients, thereby altering the microbiome and hence leading to development of respiratory diseases. So, microbiome dysbiosis could be the initial trigger of generating immune response and development of respiratory disease in the later stage.
Incoming of a new spray?
Now that we know the role of microbial players in maintaining respiratory health, it is important to modulate nasal microbiome towards a healthier state. As for maintain gut health, probiotics are considered as safe option for next generation therapeutics, they indicated beneficial effect for nasal microbiota as well, via both oral and intranasal administration. Specifically, commonly known friendly bacteria Lactobacillus has been demonstrated as a beneficial microbe in nasal habitat. So, maybe we can think of a probiotic spray as a potential for treating the nasal conditions.
“If you have a healthy microbial community fighting for you then you will win or recover soon.”
